How To Store Solar Energy At Night: Battery Storage

For years, the big question regarding solar energy was, “What happens at night or on a cloudy day?” In truth, that used to be a legitimate concern. In recent years, however, that question has been successfully answered by combining solar energy with battery storage. 

Improvements in battery technology and the development of new battery chemistries have led to greater benefits from pairing solar energy with battery storage systems. In fact, these advancements have brought the cost of solar and storage in line with the cost of energy from the utility grid while offering additional benefits for most users. 

The Rationale for Storing Solar Energy in Batteries:

The two most common reasons customers seek out solar plus battery storage energy are: 

1. Resiliency issues: Brownouts and blackouts, energy disruption due to remote site location or power outages from natural disasters can compromise secure power for critical infrastructure or services. We recently completed Phase 1 of a project that successfully integrated a solar microgrid utilizing battery storage backup for the Bad River Tribe of Chippewa Indians in far northern Wisconsin. Read our project summary to learn more.
2. Peak demand charges: Energy use during peak demand times can be expensive. Peak demand charges are charges for the highest level of electricity needed during a billing period. They are designed for utilities to recover some of the costs associated with providing sufficient electricity generation and distribution capacity to their customers. Solar energy can supplement or replace grid power during hours of high energy use. Read about how Bergstrom Automotive—a top 50 automotive retailer in the country—partnered with EnTech Solutions to install clean-energy EV charging systems to prepare for the launch of several electric vehicle models and mitigate a spike in utility costs from EV charging.

Benefits of Storing Solar Power

Solar power paired with an appropriate battery storage system can serve as the ideal solution to these and other common concerns in a variety of ways: 

• Backup generation: If you couple your solar grid with a storage option, you can tap into that backup storage to improve your energy resiliency. Our team researches your specific situation to understand the typical outage duration of your area to choose a battery that will meet your needs effectively. We also help you prioritize which loads require backup generation and which loads could power down for short periods of time to conserve energy use during an outage. 

• Reducing generator costs: If your facility is susceptible to longer outages, or if you need to protect a critical system or service, then you may still require a traditional generator as part of your backup energy solution. However, using a battery for solar storage can offset your fuel costs in several ways. For example, you can tap into the renewable energy battery storage first and only use the generator as needed during longer outages. In addition, if you run out of stored energy, you can maximize the efficiency of your diesel generator by running it at 100%—its most efficient usage—to recharge the battery. This approach helps avoid a situation called “load following,” when the generator runs even when certain systems aren’t in use, resulting in a significant loss in efficiency and higher fuel costs than necessary. 
• Time-of-use shifting: When generating energy using solar panels during the day, you can store any excess capacity and draw it from the charged battery system at a time of day when grid energy is more expensive. 
• Peak demand shaving: As your business approaches the threshold for incurring peak demand charges, you could instead tap into the solar-charged battery to pull just enough energy to avoid reaching that threshold. Anecdotal evidence has shown that organizations can reduce their electricity bill by 20-50% using this strategy to avoid peak demand charges. 

These strategies can serve as valuable benefits to any organization trying to improve energy resiliency while controlling, or even reducing, costs. Additionally, EnTech Solutions’ proprietary techniques enable us to prioritize those strategies in real time to meet your energy needs every second of every day. Please contact us for more information about how EnTech can support your energy needs.